How did the formaldehyde applied in textile?
2015-11-09 08:44 | writer: admin
While garment is in resin finish, the formaldehyde is widely used. In order to reach the crease resistant, shrink resistant and flame resistant properties, or in order to keep the durability of printing and dyeing, or in order to improve the hand feel, the formaldehyde is need to join the finish while producing the garment fabric.
Now pure cotton fabric need formaldehyde dye auxiliaries most, because the pure cotton wrinkle easily, using formaldehyde auxiliaries can improve the stiffness of cotton fabric, that will achieve the non-ironing and wrinkle resistant properties. While people wearing and using the fabric which contain formaldehyde, the fabric will release free formaldehyde gradually, then the formaldehyde can cause airway inflammation and scytitis through respiratory or skin contact, the formaldehyde will also irritating to eyes. The formaldehyde can cause irritability or even cancer. The manufacture using dyeing auxiliaries, especially some manufactures use the high formaldehyde agent in order to reduce the cost, is very harmful to human body.
Applications of formaldehyde
Formaldehyde is a general chemical production which is widely used, easy produced and raw material adequate supplied, it can be used for disinfection, sterilization,preservative, and also used in kinds of industries as organic synthesis, synthetic material, coating, rubber, pesticide etc, its derivative products mainly including paraformaldehyde, polyformaldehyde, phenolic resin, urea formaldehyde resin, amino resin, Urotropine and Polyols etc.. Artificial board industry is well developed, it need a large amount of formaldehyde.
Formaldehyde got a wide application, it is in the course of producing synthetic resin, surfactant, plastics, rubber, leather, paper making, dyes, pharmaceuticals, pesticides, photographic film, explosives, construction materials and disinfection, fumigation, anti-corrosion, the formaldehyde is a generalist in chemical industry, but anything must got a limit and a standard, once it is over the limit, it will bring harm.
According to experts, Chinese researchers have developed non-formaldehyde wash and wear finisher, and non-formaldehyde environment-friendly urea-formaldehyde resin, while they are not mass-produced, the main reason is high cost, thus, the cheap price block the formaldehyde alternative process.
The Formaldehyde Limit in Textile Dyeing Auxiliary
About formaldehyde, Chinese standard GB18401 got a clear and strict regulation to all kind of garment.
The fabric auxiliary which contain formaldehyde content larger than 30ppm should not have contact to skin, any fabric auxiliary formaldehyde content should not larger than 300ppm, such as wool protective agent, solid color punishment, crosslinking agent, adhesive etc..
Limit the formaldehyde content which is dissociative or part hydrolysable, make sure the formaldehyde content which is dissociative or part hydrolysable to the skin contact fabric formaldehyde content should not over 30ppm, and for other fabric should not over 300ppm.
Heavy metallic salt (except iron) or formaldehyde cannot be used as decolourizing agent or fadeometer in fabric.